The present invention relates to a camera control device and, more particularly, to a camera control device for controlling the imaging (photographing) direction (panning and/or tilting) and the magnification (zooming).
Conventional means for remotely controlling the panning and/or tilting and zooming of a video camera include an operation lever, a joy stick, and a push button switch, each of which corresponds to rotations on two axes, and a button on a display which imitates any of these devices. When these devices are used, the rotational angle or the angular velocity is made correspond to the angle of the lever, or a rotation in a desired direction, such as a vertical or horizontal direction, is performed while the button is pushed. Analogously, zoom control is done by using a button or the like device which designates an operation to the wide-angle side or the telephoto side.
When, for example, panning or tilting is performed using the camera operating means or control device as described above, the camera pans or tilts in accordance with the operation, so the device is suitable for an operation which the user performs while monitoring the monitor screen. However, the device is inappropriate to operate or control a camera to a target position regardless of the current camera position.
Another method is possible in which the angles of a panning and tilting are directly input as numerical values and a camera is moved to the corresponding position under the control of a control device. In this case, however, an operator cannot sensibly recognize which region in the movable range of panning/tilting is within the field of view.
In remote diagnoses or television conference systems in which the circumstances of remote places need to be picked up by television cameras, an object to be picked up moves or objects are changed in many instances while a motion image is taken from a video camera and displayed on a display. In these cases, a user on the camera side need not always confirm the picking up range by directly monitoring the motion image on the display, since the user can identify the picked up object to some extent by checking the direction of the camera. However, if the camera is located in a remote place from both the display and the user, the user must change an object to be picked up by remotely changing the direction of the camera while monitoring the screen on which the motion image currently being picked up is displayed.
In these instances, the direction of the camera can be controlled more easily if the user can see not only a motion image within the limited range which can be picked up by the camera at once but also the circumstances over a wide area in the remote place capable of being picked up by the camera. Additionally, the presence is improved and the atmosphere is better understood when not only an object of interest but the scene in an entire remote place are displayed on the screen.
The circumstances over a broader range in a remote place cannot be communicated by motion images unless motion images taken by a wide-angle camera are displayed. Unfortunately, when the atmosphere is communicated by using wide-angle motion images, an object of interest also is displayed as a small image.
Methods by which this is prevented are to selectively display an image of an entire atmosphere (wide-angle) and an enlarged image (standard or telephoto) on a single display (or display window), and to simultaneously display two images taken by wide-angle and standard (or telephoto) cameras on two displays (or display windows). It is unfortunate that transmitting wide-angle and standard images using two cameras requires pairs of cameras, camera control devices, and image transmission lines.
To realize this with a single camera, the following methods are possible.
(1) Transmit a high-resolution motion image and display the image on a high-resolution, large screen.
(2) Transmit a high-resolution motion image and enlarge, where necessary, only an object of interest on the display side.
(3) Transmit a motion image with a normal pixel density and enlarge a portion of the image on the display side.
(4) Change the zoom ratio of a camera in a remote place.
In methods (1) and (2) described above, however, it is necessary to transmit motion images with a high definition (= large capacity). Consequently, in method (2) the image quality is degraded when an image is displayed in an enlarged scale. Also, in the methods other than method (1) it is not possible to simultaneously check the motion image over a wide area and the point of interest, i.e., two different images of wide-angle and standard ranges.
It is a principal object of the present invention to provide a camera control device and method which solve the above conventional problems.
That is, it is an object of the present invention to provide a camera control device capable of simply and rapidly controlling a camera to a target state regardless of the current camera condition.
It is another object of the present invention to provide a camera control device capable of clearly presenting to an operator a imaging visual field obtained by the control to the target state.
A camera control device according to the present invention is a camera control device for controlling a camera capable of at least panning and tilting, comprising display means for displaying a first frame which indicates a potential maximum imaging visual field defined by limits of panning and tilting, and a second frame which indicates a current imaging range at a position inside the first frame and corresponding to current imaging conditions. This camera control device further comprises operating means for operating the second frame displayed on the display means, and control means for controlling the camera in accordance with the position of the second frame operated by the operating means.
The above camera control device preferably further comprises means for inputting an image in the maximum imaging visual field while moving the camera within the limits of panning and tilting at a predetermined timing, and displaying the input image in the first frame. The predetermined timing is, for example, when camera control is started, when an operator inputs a specific instruction, and/or when a camera operation input is determined.
Furthermore, the camera comprises an externally controllable zoom function, and the display means displays a first frame which indicates a potential maximum imaging visual field defined by the limits of panning and tilting and a wide-angle end of zooming, and a second frame which indicates a current imaging range inside the first frame and having a position and a size corresponding to current panning, tilting, and zooming conditions.
Alternatively, a camera operation area is set inside and/or in the vicinity of the second frame displayed on the display means and operated by operating means consisting of a pointing device such as a mouse, thereby updating the display of the second frame and controlling the camera.
By the use of the above means, an operator can intuitively recognize which part in a range which can be picked up by panning and tilting is currently being picked up. Also, the direction and zoom of the camera are controlled by operating the second frame for displaying the current imaging range, so the camera can be directly aimed in a direction of interest. These functions greatly improve the operability of the camera.
Furthermore, when an object to be picked up in the maximum imaging visual field is previously picked up and displayed in the first frame, an operator can select a portion which he or she intends to image more properly and can control the camera in the corresponding direction and to the corresponding zoom value.
It is still another object of the present invention to provide a motion image display apparatus capable of communicating the circumstances over a wide area in a remote place by transmitting a portion of interest as a motion image and the other portion as a still image, and also capable of efficiently displaying the motion image.
To achieve this object, a motion image display apparatus of the present invention comprises motion image inputting means for inputting a motion image, imaging direction changing means for changing an imaging direction of the motion image inputting means, synthesizing means for synthesizing one still image in a wide area on the basis of motion images in various directions previously taken by changing the imaging direction of the motion image imaging means, display means for displaying the still image synthesized by the synthesizing means in a still image area, and displaying a motion image currently being taken by the motion image inputting means in a motion image area superposed on a position corresponding to a current imaging direction in the still image area, motion image area moving means for moving the motion image area within the still image area, and control means for controlling the imaging direction changing means on the basis of position information of the motion image area moved by the motion image area moving means so that the imaging direction of the motion image imaging means corresponds to the position of the moved motion image area, and updating a portion of the synthetic still image corresponding to the motion image area before being moved, as a still image, by using the motion image displayed in the motion image area before the imaging direction is moved.
In this arrangement, when the motion image area moving means moves the motion image area, the control means controls the imaging direction changing means on the basis of the position information of the moved motion image area so that the imaging direction of the motion image imaging means corresponds to the position of the moved motion image area. The control means also updates a portion of the synthetic still image corresponding to the motion image area before being moved, as a still image, by using the motion image displayed in the motion image area before the imaging direction is changed. Accordingly, even if motion image display processing on a large screen is slow or a motion image in a wide area is difficult to display with a high definition because the motion image transfer rate is not so high, an image over a wide area which communicates an overall atmosphere is displayed as a still image, and a portion of interest is displayed as a motion image. Additionally, since the still and motion images are displayed by synthesizing them while their positions and sizes are matched as if a portion of the still image is replaced with the motion image, an efficient motion image display is possible with little computer resources. Also, not the whole synthetic still image but only the portion of interest is updated, so only a small data amount needs to be updated.
In the above apparatus, the whole synthetic still image can be periodically updated by scanning a imaging area corresponding to the still image area by using the motion image imaging means.
Also, in the motion image display apparatus, the whole synthetic still image can be updated by scanning a imaging area corresponding to the still image area by using the motion image imaging means, while a motion detecting means is not detecting a motion of an object.
Other features and advantages of the present invention will become apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.